Apparatus for routing cables in wind turbines

ABSTRACT

An apparatus for routing cables in wind turbines, in which a plurality of bushings ( 17 ) for at least one cable are distributed on at least one base body ( 3, 5 ) that has a preferably round contour, characterised in that the bushings ( 17 ); are provided with a guiding arrangement ( 27; 38; 39; 41; 43; 48 ) which permits the respective cable to move relative to the part of the bushing ( 17 ) that surrounds the guiding arrangement.

The invention concerns an apparatus for routing cables in wind turbines, in which on at least one base body, which has a preferably circular outline, multiple cable bushings are distributed.

For the purpose of discharging the energy generated in wind turbines, as well as for other operational purposes such as control, monitoring etc., the cables that run down through the tower from the nacelle must be routed such that when the cables, which hang in form of cable bundles from the nacelle inside the tower, move during operation they are not damaged or impaired in any way. Since in commonly used wind turbines the nacelle with the generator unit, from which the cable bundle hangs inside the tower, can make up to three turns before the nacelle is driven back, the cable bundle must be routed such that the cables inside the bundle, hanging in the tower, are, on the one hand, able to follow the movement, but, on the other hand, do not chafe against each other to the degree that the insulation may be damaged.

To this end, in the poor art, for example as described in WO 2011/151465 A2, the cables are led, spaced from each other, from the rotatable nacelle in a cable bundle to a base body that is non-rotatably supported inside the tower, and fed through bushings that are arranged on said base body, in which the bushings are disposed, spaced from each other, so that the cables inside the bundle are also spaced from each other. As the bundle twists with the rotating movement of the nacelle, the danger of chafing between the cables is largely prevented. Nevertheless, the sudden change in direction of the cables, which is caused by the twisting of the bundle at the location where the cable exits the bushings of the base bodies, leads to undue local stress on the cables and their insulation.

With respect to the above described problem, it is the object of the invention to provide a guiding apparatus that ensures the best possible protection of the cables during the twisting movements of the cable bundle.

This object is achieved according to the invention by an apparatus with all the characteristics of claim 1.

According to this a significant feature of the invention is that the bushings are provided with a guiding arrangement, which permits cable movements relative to the part of the bushing that surrounds the guiding arrangement. This prevents the cables from being forced at the exit from the bushing into a sudden change in direction that is similar to kinking, since the free movement within the bushing permits a gradual change in direction.

In particularly advantageous exemplary embodiments the respective guiding arrangement is provided with an insert that surrounds the cable passing through, where said insert is moveably supported in the respective bushing relative to the base body.

In particularly preferred exemplary embodiments the insert is made in form of an annular body that surrounds the cable passing through it, where the outside surface of said annular body forms part of a convex, spherical surface on which a part of a wall of the inside of the bushing is supported, forming a spherical cap. This creates a ball joint-like guide for the cable, providing the cable with freedom to move around any axes.

Alternatively, an arrangement may be provided in which the guiding arrangement is fitted with an elastomeric, annular body that flexibly surrounds the cable in the bushing, preferably made of a synthetic rubber material. The guiding of the cable through a type of collar can be achieved with little effort and is thus a very cost-effective solution.

According to a further advantageous exemplary embodiment the guiding arrangement is provided with a swivel bearing for the cable passing through. To this end the arrangement may be implemented with particular advantage in that the swivel bearing is provided with a needle bearing, the inner ring of which surrounds the passing cable, and the outer ring of which is fixed to the base body. This allows the cables that pass through it to adjust their turning position to the rotating movements of the bundle in a particularly gentle manner.

In an alternative exemplary embodiment the guiding arrangement may comprise rotatable roller bodies that are arranged such that they form lateral boundaries of the cable passage of the respective bushing. Hence the bushing for the passing cable is provided with moveable walls.

In a particularly simple and cost-effective solution the arrangement can be implemented such that the bushings are formed by circular openings in a circular disk that forms the base body, in which the guiding arrangement is formed by the openings, and the wall of the openings curve and expand outwards on both sides. Thus each cable that passes through the bushing is able to adjust to any inclination relative to the plane of the base body.

In a further modified exemplary embodiment the base body is provided, along its circular circumference, with adjacently located holding fixtures that are radially open in outward direction. Said holding fixtures are provided for the purpose of inserting and retaining bushings whose cable passages can be opened to allow the insertion of the respective cable. Such exemplary embodiments are characterized by being particularly easy to install, since the threading of individual bundle elements through closed cable passages is not necessary. This also enables easy retrofitting in existing plants.

In particularly advantageous exemplary embodiments the bushings are formed by two partial bodies that delimit the opening of the cable passage so that the cable passages can be opened, and where the two partial bodies can be locked in the respective holding fixture in a position that closes the opening.

Said partial bodies may be shaped as identical parts, each of which forms one half of the bundle bushing.

To securely lock the bushings in the holding fixtures, advantageous exemplary embodiments are provided with a locking strap that surrounds the circumference of the base body and fits tightly against the, in radial direction on the outside located, partial bodies of the bushings.

To account for the fact that the cable bundle becomes shorter as it twists, particularly advantageous exemplary embodiments provide that at least one base body is attached to the swiveling nacelle located on the tower of the respective wind turbine, and at least one base body disposed further down is attached such that it is non-rotatable and vertically moveable inside the tower.

In this respect the arrangement can be designed particularly advantageously in that radially protruding rollers are provided on the edge of the vertically moveable base body at diametrically opposed locations. The rollers are guided in vertical runners inside the tower. The base body is thus non-rotatably supported with respect to the tower, but it is able to assume the appropriate vertical position depending on the respective length of the cable bundle.

The invention is now explained in further detail by way of exemplary embodiments depicted in the drawings. Shown are in:

FIG. 1 a schematically very simplified representation of a cable bundle, which hangs from the nacelle of a wind turbine inside the tower and is guided by an apparatus according to an exemplary embodiment of the invention;

FIG. 2 a representation corresponding to FIG. 1 in which the cable bundle is shown in a twisted state:

FIG. 3 an oblique, perspective view of a base body according to an exemplary embodiment of the apparatus according to the invention, in which the base body is supported non-rotatably and vertically moveable inside the tower;

FIG. 4 a partial cross-section of the base body along line IV-IV of FIG. 3, drawn enlarged compared to FIG. 3;

FIG. 5 an oblique, perspective view of a base body according to a further exemplary embodiment of the apparatus according to the invention;

FIG. 6 cross-section of the base body of FIG. 5, drawn in oblique, perspective view;

FIG. 7 an oblique, perspective view of a base body according to a further exemplary embodiment of the apparatus according to the invention;

FIG. 8 a partial representation of the base body of a further modified exemplary embodiment of the apparatus drawn in an enlarged, oblique, perspective cross-section;

FIG. 9 an oblique, perspective view of the base body according to a further modification of the invention;

FIG. 10 an oblique, perspective view of the base body according to an even further modification of the invention;

FIG. 11 an oblique, perspective view of a further exemplary embodiment of the invention similar to that of FIG. 3;

FIG. 12 a plan view of the exemplary embodiment of FIG. 11;

FIG. 13 a cross-section along line XIII-XIII of FIG. 12;

FIG. 14 a separated, oblique, perspective view of an annular body in a modified, two-part design;

FIG. 15 a partial representation in an oblique, perspective view in which only the base body and a single runner of a further modified exemplary embodiment of the invention are shown;

FIG. 16 a partial cross-section of the exemplary embodiment of FIG. 15, drawn enlarged compared to FIG. 15 and in an oblique, perspective view;

FIGS. 17 & 18 oblique, perspective views of the sliders provided in the example of FIG. 15 and 16, showing the rear view and the front view of the depicted slider;

FIG. 19 an oblique, perspective view of a further modified exemplary embodiment of the invention similar to that of FIGS. 5 and 10;

FIG. 20 a plan view of the base body of the exemplary embodiment of FIG. 19 shown separately without bushings inserted;

FIG. 4 an oblique, perspective view of a single bushing, drawn enlarged compared to FIG. 19; the bushing shown in FIG. 21 in which the two partial bodies of the bushing are pulled apart, and

FIG. 23 a perspective partial view drawn to the same scale as FIGS. 21 and 22, showing a bushing inserted into a holding fixture of the base body in cross-section through a radial plane.

FIGS. 1 and 2, which depict an exemplary embodiment of the guiding arrangement according to the invention, only show a cable bundle 1 that hands from the nacelle into the tower, and the components of the guiding arrangement according to the invention that interact with the cable bundle 1. The remaining components of the respective wind turbine, such as nacelle, rotor, tower etc. are not shown in the present drawings since they may be of a standard design. The cable bundle 1 is guided between an upper base body 3, which is attached to the rotatable nacelle (not shown) and is vertically unmovable, and a lower base body 5, which is non-rotatably fixed to the tower (not shown) but is vertically moveable.

To this end a pair of rollers 7 each is provided on diametrically opposed locations of the lower base body 5, which are vertically offset to one other and are guided in runners 9 that are attached to the tower and extend in vertical direction. Whilst in FIG. 1 the cable bundle 1 is shown in a non-twisted, stretched state, FIG. 2 shows the state in which the nacelle, and thus the upper base body 3, have swiveled so that the cable bundle 1 is twisted. Due to the shortening of the cables caused by the twisting, the lower base body 5 in FIG. 2 has moved vertically upwards along runners 9 to compensate for the change in length. The design of the upper base body 3 can be the same as that of the lower base body 5 with the exception that rollers 7 with the respective brackets are attached to the lower base body 5.

FIGS. 3 and 4 show the design of the base body 5 according to a first exemplary embodiment of the apparatus according to the invention in greater detail. The base body 5 comprises an intermediate body in form of a disk 11, which starting from a center section with a central opening 13, is provided with radially outwards extending spokes 15 (see FIG. 4), which leave room between them for bushings 17, of which the present example shows eight bushings 17 evenly distributed in a circle. The bushings 17 are each formed between the spokes 15 by circle segments 19, which are secured from both sides to disk 11. Said circle segments 19 fit together neatly without gaps and, due to their arc-shaped peripheral edge, provide the base body 5 with a circular outline. To ensure that the circle segments 19 form a ring structure where the abutting circle segments 19 are locked together, a locking strap 21 is placed around the outer circumference of the structure, which can be tensioned by means of a turnbuckle 23.

As is most clearly apparent from FIG. 4, the wall 25 of the circle segments 19, which delimits the cable passage of the formed bushing 17, has a convex shape that forms a portion of a spherical cap. An insert, which surrounds the cable that passes through the respective bushing 17, takes the shape of an annular body 27 the outside of which forms part of a convex spherical surface 29 (see FIG. 4) with which the annular body 27 lies against the concave wall 25 of circle segment 19. Thus the annular body 27, which forms the insert, is supported on the respective base body 3, 5 like a ball joint so that the cable running through the bushings 17 can take on any inclination with respect to the plane of the base body 3, 5 and can also twist together with the insert (annular body 27)

FIGS. 5 and 6 depict a further exemplary embodiment, which differs from the previously described example mainly in that a disk 31 is provided that is not star-shaped, as is the case with the disk 11 of the previously described example, but forms with the outer edge 33 itself the circular outline of the base body 3, 5. Apart from the central opening 13, further openings in disk 31 are provided to form the bushings 17. As in the previously described example, the guiding arrangement or the bushings 17 is each formed by an insert in form of an annular body 27, the outside of which is again part of a spherical surface 29.

In the example of FIGS. 5 and 6, ring elements 35 are attached to the lower and upper side of the disk 31 instead of the circle segments 19 provided in the previously described example. Said ring elements 35 again are provided, like the circle segments 19 of FIGS. 3 and 4, with internally concave walls 37 so that the annular bodies 27 are supported similar to ball joints. This embodiment does not provide a locking strap that surrounds the circumferential edge 33 of the disk 31. A further difference is that the central opening 13 of disk 31 can also be used to form a bushing 17 because this opening 13 is also provided with ring elements 35 with a cap-like curved inner wall 37, so that a ball joint-like guiding arrangement can be formed through inserted annular bodies 27.

FIG. 7 shows a further modified exemplary embodiment in which, again, a disk 31 is provided with an outer edge 33 that determines the circular outline. A rubber ring is inserted as a guiding arrangement into each of the openings provided for the bushings 17. This provides flexible guidance for the cable in an elastomeric collar so that the cable is able to assume the required inclination with respect to the plane of disk 31.

In a further exemplary embodiment shown in FIG. 8, in which, again, a disk 31 with a circumferential edge 33 is provided, the guiding arrangement of the bushings 17 is formed in each case through a swivel bearing for the cable bundle, in which a needle bearing is provided, the outer ring 39 of which is fixed to the disk 31 and its inner ring 41 surrounds the respective cable bundle.

FIG. 9 shows a further modified exemplary embodiment in which, again, a disk 31 is provided, which defines the circular outline of the base body 3, 5 with its outer edge 33 Triangular-shaped openings are formed in disk 31 for the bushings 17, where rotatable roller bodies 43 are arranged on the sides of the triangles, at the top and at the bottom of the disk 31, in such a way that the roller surfaces form the contact surface for the respective cable passing through it. The guiding arrangement of this design also provides possibilities for the inserted cable to carry out movements relative to the remaining part of the base body 3, 5.

And finally, FIG. 10 depicts an exemplary embodiment that is characterized by a particularly simple design. The single-piece main component of base body 3, 5 is in this instance a circular plate 45 that comprises round openings 47 for the bushings 17. The guiding arrangement for the cables passing through it is in this instance formed by giving the wall of the opening 47 a special shape, that is, through curvatures 49, which enlarge the openings 47 towards the outside and thus provide the passing cable with a predefinable inclination on exiting the openings.

Whilst the details of the base bodies 3, 5 are described in FIGS. 2 to 8 and 10 by means of base body 5, which, fitted with rollers 7, is arranged non-rotatably below base body 3, which can rotate together with the nacelle, it is self-evident that all of the described designs of the base body without lateral rollers 7 can also be used as the upper base body 3, as shown in the example depicted in FIG. 9.

The FIGS. 11 to 13 show a further exemplary embodiment in which the base body 5 is formed from two identical disks 51 that are arranged one on top of the other. The disks 51 form a star-shaped body with a slot on one side, so that the bushings 17, which are arranged along the perimeter of disks 51, are open to the outside via slots 53 (not all have reference numbers).

FIG. 14 shows a modified embodiment of the annular bodies 27. As depicted, the annular bodies 27 are formed from two identical ring halves 55 that can be attached to each other by way of pins 57 that are protruding from the connecting surfaces, and their matching bores 59.

When describing the bushings 17 in base body 3, 5 above, it does not only mean bushings that are arranged inside the base body, but also those that are arranged along the edge (not shown), which provide cable guidance with a further degree of freedom compared to the known, rigid guide designs. Provided that the base body has a slot at the edge in the vicinity of the bushings, the insertion of a cable from the side via the slot is possible.

The FIGS. 15 to 18 show a further exemplary embodiment in which the base body 5 is formed by a circular plate 45, as in FIG. 10. In contrast to FIG. 10, however, the plate 45 is not moveably guided by way of pairs of rollers 7 on runners 9, but each pair of rollers 7 is replaced by a slider 71 the shape of which can be seen in detail in FIGS. 17 and 18. The runners 9, of which only one is shown in FIGS. 15 and 16, take the shape of a C-profile in contrast to the example in FIG. 3, in which the runners 9 are shaped as a U-profile. The sliders 71, which are injection-molded from plastic as a single piece, are comprised of a front sliding shoe 73 and a rear guiding part 75. The latter forms parallel guiding surfaces 77 with which the slider 71 is guided inside the open slot of the C-profile of runners 9. Moreover, the guiding part 75 serves as an attachment means that has bolt holes 79, which extend all the way to the front side of sliding shoe 73 and end in expanded hexagonal recesses 81, which are designed to receive the hexagonal head of mounting bolts 83. As is best seen in FIG. 16, the mounting bolts 83 are used to fasten the respective slider 71 to brackets 85, which are formed from folded sheet metal, and which in turn are bolted to the plate 45.

As shown in FIGS. 17 and 18, the sliders 71 are provided at the front with convex-curved sliding surfaces 87 (FIG. 18) and on the back with corresponding convex-curved sliding surfaces 89 (FIG. 17), with which the sliders 71 are guided along the inner wall of the C-profile of runners 9. Said curvature of the sliding surfaces 87 and 89 allows plate 45 to slant to permit a limited angular pulling of the cables, which have been inserted into bushings 17, without tilting.

The FIGS. 19 to 23 show a further exemplary embodiment of the invention, which differs from the previously described examples mainly in that the bushings 17 are designed such that the opening 47, formed to allow the bundle elements to pass through, can be opened. Moreover, the bushings 17 are arranged such on the periphery of the base body 5 that, in the open state of opening 47, bundle elements can be inserted from the outside of the base body 5 before the opening 47 is closed.

FIG. 19 shows this exemplary embodiment without inserted bundle elements, with the bushings 17 in the closed state. Said bushings 17 are arranged along the perimeter of base body 5, and the assembly is held together by a locking strap 21 placed around the outside, as per the example shown in FIG. 3. The locking strap 21 in the present example can be closed or opened through a quick-release fastener 22 without using tools.

The FIG. 20 shows the base body 5 separately without inserted bushings 17. The base body 5 is designed as a star-shaped body, preferably made from injection-molded metal alloy. The base body 5 comprises an internally located, non-circular ring element 24, presently in the form of an octahedron, where an attachment 26 extends radially from each of the eight corners 18, away from the center of the ring element 24. The attachments 26 are approximately triangular in shape, each with two arms 28 extending from the corners 18. Said arms 28 are connected to each other through braces 30 at their radially outer ends and in a center section. The arms 28 of adjacent attachments 26 extend parallel to each other and demarcate between them and the ring element 24 a holding fixture 32 for a bushing 17 to be inserted there.

The FIGS. 21 to 23 show the bushings 17 in greater detail. They consist of two partial bodies 34 that are injection-molded from plastic as identical parts. Every partial body 34 forms a clamp which, in a closed position, as shown in FIG. 21, forms one half of the opening 47, is the bundle passage. in the closed position, as shown in FIG. 22, the pins 36 and the bore holes 40 engage at their respective contact surface. This provides mutual guidance to compensate for manufacturing tolerances. On the two sides that are facing the arms 28 when the partial bathes 34 are inserted into the holding fixture 32 in operating position, the partial bodies 34 each form a channel 42 (see FIG. 21) laterally delimited by guiding rails 44. When inserting the bushings 17 into the holding fixtures 32, the respective arm 28 of the attachment 26 of base body 5 is received in said channel 42. Bevels 46 at the end of the guiding rails 44 facilitate the sliding of the bushings 17 onto the arms 28. A flexible latching clasp 48 is formed inside each of the channels 42 on each partial body 34. A catch 50 protruding to the outside is located in close proximity to the flexible, free end of the latching clasp 48. As can be seen from FIG. 20, and in particular from FIG. 23, said catch 50 is provided to interact with latching grooves 62, which are located on the arms 28 of the attachments 26 of base body 5. A channel 64, which is laterally bounded by a rib structure 66, is also formed on the other sides for the engagement of the ring element 24 of base body 5, as shown in FIG. 21, top and bottom, and in FIG. 22 on the side.

For the installation of the bushings 17 in this design, a partial body 34 is pushed onto the respective arms 28, where said partial body 34 interlocks with the latching grooves 62 that are adjacent to annular body 24, and is thus already prevented from slipping out. The bundle elements can now be inserted easily from the outside and the second partial body 34 is pushed onto the arms 28 to close the opening 47, which causes the locking of the outer latching grooves 62, thus preventing the bundle elements from falling out of the holding fixtures 32. To completely secure the thus formed unit, a locking strap 21 can be placed around the outside and secured by way of the quick release fastener 22. As shown in FIG. 19, the rollers 7 in this exemplary embodiment that are provided for guidance in the runners 9 in the tower are, differently to the above described examples, not attached to the base body 5, but are attached to the locking strap 21. 

1. An apparatus for routing cables in wind turbines, in which multiple bushings (17) for at least one cable are distributed on at least one base body (3, 5), which has preferably a circular outline, characterized in that the bushings (17) are provided with a guiding arrangement (27; 38; 39, 41; 43; 48), which gives the respective cable freedom to move with respect to the part of the bushing (17) that surrounds the guiding arrangement.
 2. The apparatus according to claim 1, characterized in that the respective guiding arrangement is provided with an insert (27) that surrounds the inserted cable and which is moveably supported in the associated bushing (17) relative to the base body (3, 5).
 3. The apparatus according to claim 1, characterized in that the insert is designed as an annular body (27) that surrounds the inserted cable, where the outside of said annular body (27) forms part of a convex spherical surface (29) with which it is supported on the wall (25), which forms part of a spherical cap, on the inside of the bushing (17).
 4. The apparatus according to claim 1, characterized in that the guiding arrangement is provided with an elastomeric ring (38), which flexibly surrounds the cable passing through the bushing and which is preferably made from a synthetic rubber material.
 5. The apparatus according to claim 1, characterized in that the guiding arrangement comprises a swivel bearing (39, 41) for the cable passing through it.
 6. The apparatus according to claim 1, characterized in that the swivel bearing comprises a needle bearing whose inner ring (41) surrounds the cable passing through it, and whose outer ring (39) is fixed to the base body (3, 5).
 7. The apparatus according to claim 1, characterized in that the guiding arrangement comprises rotatable roller bodies (43) that are arranged on base body (3, 5) in such a way that they form the lateral boundary of the passage through the respective hushing (17).
 8. The apparatus according to claim 1, characterized in that the bushings (17) are formed by round openings (47) in a round plate (45) that forms the base body (3, 5), and that the guiding arrangement is formed in that the walls of the openings (47) are provided with outward-directed curvatures (49) that expand the openings on both sides.
 9. The apparatus according to claim 1, characterized in that the base body (5) is provided along its circular outline with adjacently located holding fixtures (32) that are radially open to the outside, and where bushings (17) can be inserted and locked inside said holding fixtures (32), and where the passages (47) of bushings (17) can be opened to enable the insertion of the respective cable.
 10. The apparatus according to claim 1, characterized in that the bushings (17) are formed by two partial bodies (34) that delimit the opening (47) of the passage and permit the opening of said passages, and where said partial bodies (34) are lockable in the respective holding fixture in the position that closes the opening (47).
 11. The apparatus according to claim 1, characterized in that the partial bodies (34) are formed as identical parts.
 12. The apparatus according to claim 1, characterized in that a locking strap (21) is provided to secure the bushings (17) inside the holding fixtures (32) by surrounding the circumference of base body (5) and thus pressing against the partial bodies (34) of the bushings (17) located radially on the outside thereof.
 13. The apparatus according to claim 1, characterized in that at least one base body (3) is attached to the rotatable nacelle on the tower of the associated wind turbine, and that at least one base body (5), arranged further below, is supported inside the tower in a non-rotatable and vertically moveable manner.
 14. The apparatus according to claim 1, characterized in that radially protruding rollers (7) are attached, or can he attached, to the edge of the vertically moveable base body (5) in diametrically opposed positions, and which are guided in vertical runners (9) inside the tower.
 15. The apparatus according to claim 1, characterized in that the radially protruding rollers (7) are attached to the locking strap (21), which surrounds the circumference of the base body (5), on diametrically opposed sides.
 16. The apparatus according to claim 1, characterized in that radially protruding sliders (71) are provided on the edge of the vertically moveable base body (5, 45) on diametrically opposed locations, said sliders (71) being guided in vertical runners (9) inside the tower. 